Yaw stability control system

摘要

The present invention relates to a yaw stability control system for a vehicle equipped with electric power assisted steering and a method of controlling it. The system comprises: means (10) for determining the occurrence of understeer; means for determining the degree of understeer after the occurrence of understeer is determined; means (20) for determining if the determined degree of understeer exceeds a threshold value; means (30) for saving the steering wheel torque value and steering wheel angle value when determined that a calculated drop in steering wheel torque (8) exceeds the threshold value; means for calculating a delta steering wheel torque (3), delta steering wheel angle (9) and updating the steering wheel angle (6) at the start of delta torque calculation; means for applying the calculated delta steering wheel torque (3) to the steering of the vehicle; means for calculating a driver intended steering wheel angle (5) and using it for controlling yaw stability control operations.